vlan+bridge questions

[John Nielsen]

> On Aug 14, 2015, at 11:57 AM, Hooshang F <ebastan10 at gmail.com> wrote:
> 
> We need to install a freebsd firewall (pf). The freebsd
> box needs to be placed in bridge mode in the middle of a VLAN truck
> link between 2 Cisco switches. The em0 and em1 ports
> are connected to the trunk ports on the 2 switches.
> 
> We are going to:
> 
> 1- Define two vlan interfaces for vlan id X.
>    one with em0 as parent and the other on top of em1.
> 2- Create a bridge interface.
> 3- Add the two vlan interfaces as members of the bridge.
> 4- Repeat 1-3 for every vlan id used in the network.
> 
> 2 questions:
> 
> 1- Is not there a simpler method which does not involve creating so
>    many vlans & bridges? For instance, is it possible to have
>    a truck interface which accepts 'all' vlan IDs (like cisco) instead
>    of creating two vlan interface per ID?
> 
> 2-  How the untagged traffic should be bridged? Cisco switches
>     send out packets untagged if vlan ID is equal to the trunk port
>    'native' vlan id. To bridge this packets, we should create
>    a bridge with em0 and em1 as members, but that will
>    effectively disables bridging on vlan interfaces. Right?

Same answer for both questions: bridge the parent interfaces. If you need vlan interfaces, create them as children of the single bridge interface.